1. Field of the Invention
The present invention relates to a semiconductor memory device, and more particularly, to an improvement of a driver circuit of a semiconductor memory device.
2. Description of the Related Art
Generally, in a prior art semiconductor memory device, a memory cell array is divided into a plurality of blocks. Each of the blocks is also divided into a plurality of memory cell columns. Each of the memory cell columns is further divided into a column switch transistor and a plurality of memory cells. Therefore, a block decoder is provided for selecting one of the blocks, a column decoder is provided for selecting one of the memory cell columns from each block, and a word decoder is provided for selecting one memory cell from each memory cell column.
Also, a column driver circuit is connected to the block decoder and the column decoder, thus generating column drive signals for the memory cell columns, and a word driver circuit is connected to the block decoder and the word decoder, thus generating word drive signals.
In the prior art driver circuits, however, the number of elements (transistors) is large or the size of each element is large, so that the total gate width of transistors of the driver circuits becomes large. This will be explained later in detail. Thus, the integration cannot be enhanced.